Praziquantel in the treatment of hepatosplenic schistosomiasis: biochemical disease markers indicate deceleration of fibrogenesis and diminution of portal flow obstruction.

Serological indicators for disease activity and portal vein obstruction and/or deviation were assessed in 23 patients with hepatosplenic schistosomiasis before, and up to 18 months after, praziquantel treatment, as well as in 25 matched local controls. Cessation of egg-induced immunopathology was reflected by the return to normal of serum procollagen-III-propeptide and neopterin concentrations. Reversibility of portal vein pathology was indicated by normal clearance of cholylglycine in cases without signs of decompensating portal hypertension. In most patients with a history of ascites and/or haemorrhage, serum cholylglycine concentration remained pathological. The results provide evidence that the fibrogenic process ceases after specific chemotherapy, and that portal vein pathology regresses in a substantial proportion of hepatosplenic schistosomiasis cases.

Release of interleukin 2 and gamma interferon by peripheral mononuclear cells in human Schistosoma mansoni infection normalizes after chemotherapy.

Interleukin 2 (IL-2) and gamma interferon (IFN-gamma) were determined in supernatants of mitogen- and antigen-driven cell cultures from patients with hepatosplenic or intestinal schistosomiasis. Skin reactivity was tested using a panel of eight recall antigens. Results were compared with those of uninfected local controls. In both schistosomiasis groups, IL-2 activity was reduced before treatment. In less than one third of the patients, schistosomal antigens elicited detectable IL-2 activity. IFN-gamma production was reduced more severely in hepatosplenic cases, in particular after stimulation by anti-CD3 monoclonal antibodies. After anti-schistosomal therapy with praziquantel, mitogen-induced IL-2 and IFN-gamma activities became normal within 3 months in intestinal schistosomiasis, and within 6 months in the hepatosplenic patient group. Results of in vivo delayed-type hypersensitivity tests paralleled those of in vitro lymphokine production. In conclusion, evidence is presented for severe, antigen-unspecific suppression of lymphokine production and skin reactivity against recall antigens. Anti-parasitic chemotherapy is shown to reverse the impairment of cell-mediated immune responses at the cytokine level.